One unlikely coincidence is usually acceptable to most audiences, especially if the writer hangs a lampshade on it.
Whereas, Tolkien is string unlikely coincidence after unlikely coincidence on purpose, in the same way that a very good writer might confidently write a run on sentence (see the description of the clock striking the hour in 'Masque of the Red Death') or a sentence fragment because they are trying to achieve some effect on purpose. And moreover, Tolkien even is carefully crafting the way the story is told so as to make the coincidences seem a bit less unlikely - all that careful world building and maps and so forth. And when Tolkien brings up luck, he's not hanging a lampshade on things in the same since that 'Order of the Stick' is.
As well, prophecy and phenomenal cosmic forces are beyond the purview of simple luck.
How would you know? Moreover, when people speak of manipulating their luck - like a lucky rabbits foot, or hanging a horseshoe over the door, or throwing a bit of salt over their shoulder - what do you think they are imagining they are manipulating? In the animist conception of the world, everything in the world that exhibits behavior is exhibiting an act of will. In this conception of the world, luck is the purview of phenomenal cosmic forces. Indeed, chance - chaos - is a primordial and preeminent cosmic force. What do you think luck is, particularly in the context of a fairy story?
If you have a mysterious force engaged in a contest with another force, and they can each conceive of some end scenario, and they can calculate the entire causal chain necessary in order to get to that point, then that shouldn't actually require retro-causality to pull off. It might be difficult to contemplate, based sheerly on the scope involved, but it's just straight-forward cause-and-effect from the moment it's all set into motion.
Agreed. But it will look like retro-causality in that the result is influences the causes.
That's not quite what this thread is about, though. Unless I've lost track of things, you want a class of character that can contribute in meaningful ways (and not die) due to the sorts of lucky coincidences that befall protagonists. Something like always having the right thing in its pockets, failing in productive ways, and being in the right place at the right time? You could do that, if it was all being controlled by a mysterious cosmic power that was working toward an end goal, but there are issues with that in an RPG.
You can do that regardless of how you flavor or skin the source of the luck, just as you can flavor or skin hit points, or saving throw bonuses, or magic as having different sources without changing the mechanics that you use to represent those things.
First of all, I've never known a pawn of prophecy to die unexpectedly against a troll.
Well, unless that was really the characters destiny all along. And so far, I've not stated in any way exactly what role the character is to have in fulfilling a prophesy, much less what the prophesy is.
You don't usually get characters with mysterious luck that only gets them halfway to a goal before it fails them.
No, you get those characters, but we don't usually read the stories about those characters - which is something else Tolkien explicitly observes in the book.
Second of all, it would be hard to let a player exercise any of that power, since the player doesn't know what the end goal is, and anything that they think might be the goal could be incorrect.
Or, everything that they think and do could be correct in the sense that it happened. There is nothing that prevents lucky guy from finding his own path, and for that matter the power behind his luck could well be some perverse thing wanting to demonstrate the absurdity and impermanence of everything. The character's luck could be some deities idea of a cosmic joke, and the pointlessness of it all could be the point. But this is mere flavor. You're reduced in my opinion to quibbling now. The point is there is a place for such a character in fantasy, and we could find ways to mechanically represent it. Arguing that the character doesn't have infinite luck, or that infinite luck would be unfair, may well be true, but doesn't invalidate the concept.
And of course, on the last point, it's not terribly satisfying to play a character that is being manipulated by fate. Protagonists in fantasy novels often express similar feelings, when they find out about it.
First, that's a player preference. I think it might well be interesting to play a character that is being manipulated by fate, and play out expressing feelings of dissatisfaction or trepidation about the whole process or any other way that a character might respond to finding out that he's a pawn in a play. Indeed, I think it might well be interesting to play a character who is not consciously in control of his own superpowers, but whose superpowers are (from the character's perspective) mysteriously manifesting in ways he doesn't control and maybe doesn't always approve of. That to me sounds like a load of fun. But secondly, how would you know whether you are being manipulated by fate, or whether you were manipulating fate? The same concept and the same mechanics could handle both types of characters - a destined character and a character that is controlling their own destiny - and indeed there is a lot of interesting tension (to me) in those two things. I could definitely see a character flip-flopping back and forth between thinking's he's mastering fate, and being mastered by it. A character that meaningfully through his mechanics is exploring the question of whether we really have free will to me sounds awesome.
So the question remains, how would you represent such a character in an RPG?
There are probably lots of ways to do it, and I'm working on a system that is flexible enough to really capture all the various nuances that a player might want to bring to the overall archetype so that the class is at least as varied as say rogue, wizard or fighter. The obvious thing is that the class has the power to manipulate the game itself. The class itself should be mediocre and very vanilla in terms of numbers of skills, combat ability, hit points, and so forth. At it's core, it doesn't excel at anything particularly. But various things I'm playing with for the 'Paragon' concept:
1) Without any special training, the character is just a preeminent example of a member of his race. The things his race is good at, he gets better at. Mechanically, I'm doing this with class abilities that depend on your race, and with racial feats being bonus feats for the class. For example, human paragons get more skill points and can flexibly select a small number of class skills. Elven paragons get improved racial bonuses to spot, search, and listen, and always treat those as class skills. And so forth.
2) Without any special training, the character just gets generally good at things. Mechanically, I'm representing this as an improved schedule of ability score enhancements.
3) Good saves. Because the character is lucky, he just tends to luckily avoid all problems.
4) Luck: In my game I already have something called a 'destiny point' that all characters receive, and can spend (and replenish) to get rerolls, turn critical hits made on them into normal hits, buy bonus dice, and other small bad luck mitigating mechanics. Most characters only have a couple and can usually afford to spend one per level gained. The Paragon gets an additional pool of points that can be spent like destiny points and which automatically replenish after each long rest. Likewise, feats that manipulate destiny point use (for example, getting additional bonus dice whenever you buy bonus dice with a destiny point) are on the Paragon's bonus feat list. Because such feats would rarely be invoked by most characters, they would rarely get chosen, but for a Paragon they are extremely useful. I'm planning to create a significant number with different flavors to represent everything from comic relief to inspiring heroes.
5) Foresight: Divination as a natural talent seems like a good way to represent luck. Augury is a very good example of a spell that is based on 'knowing the omens' or luck. This could end up as a class ability or a collection of feats or both.
6) Narrative manipulation: I'm not sure whether to make this optional abilities or core class abilities, but the idea is that player would have limited ability to alter or invent anything about the environment that hadn't previously been pinned down. The player can make a reasonable suggestion about something that could be true, but which isn't yet established, and the DM will insert that detail into the universe. If the player jumps out of the window of a building overlooking a city street, the player can spend a resource to specify that 'luckily' a hay wagon is passing underneath the window at that exact moment, and his fall will be cushioned. Or the player can specify that luckily, the drawer of the old desk contains a forgotten silver letter opener which can be used to stab the were-rat, or that an ally's carriage just happens to be passing on the street at that exact moment that they need a get away vehicle, or any other reasonable manipulation of the game universe that doesn't contradict what is already established and known to the character.
In general, I see such a character as being quite fun to play, but not necessarily (if I do my job well) stronger than any other class. It certainly can't manipulate the universe better than a wizard, but it can do so in a somewhat more flexible manner and without necessarily spending actions. It certainly can't reliably perform as many skills as a rogue nor as reliably do as much bonus damage, but it can match the rogue perhaps over short bursts. It certainly can't fight as well as the fighter, but it's not useless in combat and - like the fantasy characters that inspire the concept - it can pull through spectacularly in key moments. If you need someone to throw a boomerang basically blind and critically hit sparky-sparky-boom-man, it might be the only successful attack he makes all day, but lucky guy is the guy to save the day. In general, the idea is for a class that doesn't shine anywhere in particular and is generally weak most of the time compared to other classes, but does get to pick when it might have shining moments of awesomeness.